A wide variety of air treating compositions, both gel and non-gel types, are in use today. While the available compositions may exhibit one or more useful features, each also generally has at least one undesirable property that may limit its use. In some instances, for example, the composition may include a volatile organic solvent or carrier which has a vapor pressure of 0.1.times..sup.mm or greater at 20.degree. C. Such organic compounds, defined as VOC (volatile organic compounds), present environmental problems and are subject to regulation in many areas in the United States.
Gels have also been made from seaweed extracts (e.g. carrageenan). However, these can hold only small concentrations of fragrance oils. Furthermore, such products are not completely stable under elevated temperatures, are not transparent, and generally have poor active release characteristics. Sodium stearate based gels can hold more actives than carrageenans but are alkaline in nature and have stability problems at normally encountered elevated temperatures.
U.S. Pat. No. 4,617,147 discloses a solid perfume composition prepared by mixing together perfume oil, hydroxypropyl cellulose in alcohol solution, and a saturated solution of dibenzylidene sorbitol in N-methyl-2-pyrrolidone. While this composition offers certain advantages, it would be preferable, if possible, to avoid the use of solvents such as ethanol and N-methyl-2-pyrrolidone. Additionally, the gels of U.S. Pat. No. 4,617,147 are formed at ambient temperature and lack thermal stability.
Fragrance impregnated polyolefin systems have also been proposed. These products can hold 25-30% fragrance loads but do not efficiently release the fragrance into the air and do not have a visible end point.
Silica gels have also been proposed. While these are capable of holding high levels of fragrance oils, they do not form self-supporting structures thus leading to leakage and safety concerns.
Other gel deodorizing compositions or the like are shown in the following patent publications:
Japanese patent publications JP 62221355-A and JP 91063381-B disclose a gel fragrant deodorant composition comprising a blend of water, an alcohol, organic solvent, pigment, moisture retaining agent, dibenzylidene sorbitol, butane-diol and perfume.
Two other Japanese patent publications JP 59077859-A and JP 88064986-B disclose gelled fragrant deodorizing compositions containing dibenzylidene sorbitol, with methyl-methoxy-butanol or ethylene glycol monoethyl ether. The compositions are described as useful in, for example, vehicles, toilets, bathrooms or the like.
Japanese patent publications JP 63043666-A and JP 93060387-A disclose aromatic water-gel compositions containing dipropylene glycol alkyl ether and/or propylene glycol alkyl ether, gelling agent, perfume and water.
A gelated perfumed detergent composition comprising 12-hydroxystearic acid and/or benzylidene sorbitol, perfume, dye and surfactant is disclosed in JP 61083300-A while JP 62041661-A discloses a transparent hydrogel perfume agent for toilets, cars or the like prepared by blending carrageenan or agar, perfume, surfactant and water.
Other prior disclosures include:
JP 83025644-B and JP 48075731-A which describe gelled cosmetic products comprising dibenzol sorbitol, hydroxy propyl cellulose coloring agent and perfume while JP 60179064-A and JP 89031387-B describe gel-like perfume compositions comprising sodium behenate, a volatile terpene hydrocarbon and/or isoparaffin hydrocarbon, glycol monoether and/or ethanol, water and perfume.
EP 512770-A1 describes clear gelled stable transparent cosmetic compositions containing dibenzylidene monosorbitol mono-hydroxy alcohol(s).
GB 1243564-A discloses a transparent gel perfume which contains 8-30% primary, secondary, or tertiary phosphoric esters of 8-18 C. aliphatic alcohols, addition compounds of these alcohols with ethylene oxide or addition compounds of ethylene oxide with alkylphenols in which the alkyl group contains 8-16 C. atoms, or their mixtures. The esters are present in the form of their alkali or alkanolamine salts. The gelatinous transparent product is intended for application to the skin.
U.S. Pat. No. 4,722,835 describes a solid antiperspirant dibenzyl monosorbitol acetal gel containing a basic metal salt as stabilizer.
GB 1598449-A discloses air treatment gels, especially air freshener, containing soap, a monoalkyl ether of an alkylene glycol and one or more volatile air treatment compounds, e.g. a perfume.
Generally speaking, most, if not all, the prior air treating gel compositions include volatile organic solvents and/or alkaline salts which would preferably be avoided if an acceptable gel alternative free from such solvents and salts could be realized. The present invention provides such air treating gel compositions.